From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 159FFC4727D for ; Mon, 5 Oct 2020 13:17:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDFCD20848 for ; Mon, 5 Oct 2020 13:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601903869; bh=m6Z0F9wJ8S88qgX6o5QCjYwMEFixPhZYcGnmSMq53Ro=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=TD0Y4T+0xknJFr4Oalz2dJr0awyl2ElYnlGo2oxQBfBD09RQHDr6uQwL+IRoCXBgR nMZb5CHi57zawsRO2UrqoSfDANRfUv6idG591rXN+D0ItDmrPsNa+J1iuncQhoXo8D Cu9D8IiBJ0vGblqQcgV/rZPVBABIfup+EIRCXxxw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726074AbgJENRt (ORCPT ); Mon, 5 Oct 2020 09:17:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:35720 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbgJENRs (ORCPT ); Mon, 5 Oct 2020 09:17:48 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 920E5207BC; Mon, 5 Oct 2020 13:17:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601903868; bh=m6Z0F9wJ8S88qgX6o5QCjYwMEFixPhZYcGnmSMq53Ro=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XLEbhalAQFCWlx9/yAqmZEjWhqSX/GjwtJybHONd7qC4BIsDX0fysRT1kz3KqlCvv akG2y5DdMvEDB8zHDVmD6x4qvOIXrEFHkf3DiuuBwAw+6b0LvrrGordC+4GakKrVaS HPkxpzdt86ng/8MIGHG22YGAqlbHx3WYSDxh3yEE= Date: Mon, 5 Oct 2020 15:18:33 +0200 From: Greg Kroah-Hartman To: Steven Rostedt Cc: Naresh Kamboju , Joel Fernandes , Peter Zijlstra , Namhyung Kim , LKML , linux- stable , Sasha Levin , Masami Hiramatsu , LTP List , lkft-triage@lists.linaro.org Subject: Re: [stable 4.19] [PANIC]: tracing: Centralize preemptirq tracepoints and unify their usage Message-ID: <20201005131833.GA1506031@kroah.com> References: <20180823023839.GA13343@shao2-debian> <20180828195347.GA228832@joelaf.mtv.corp.google.com> <20200925051518.GA605188@kroah.com> <20200925105458.567d0bf4@oasis.local.home> <20200925105914.7de88d27@oasis.local.home> <20200925110706.6654954b@oasis.local.home> <20200925151245.GA3180934@kroah.com> <20200925113049.4c10c864@oasis.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200925113049.4c10c864@oasis.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 25, 2020 at 11:30:49AM -0400, Steven Rostedt wrote: > On Fri, 25 Sep 2020 17:12:45 +0200 > Greg Kroah-Hartman wrote: > > > > Specifically, commits: > > > > > > a0d14b8909de55139b8702fe0c7e80b69763dcfb ("x86/mm, tracing: Fix CR2 corruption") > > > 6879298bd0673840cadd1fb36d7225485504ceb4 ("x86/entry/64: Prevent clobbering of saved CR2 value") > > > b8f70953c1251d8b16276995816a95639f598e70 ("x86/entry/32: Pass cr2 to do_async_page_fault()") > > > > > > (which are in 5.4 but not 4.19) > > > > > > But again, is this too intrusive. There was a workaround that was > > > original proposed, but Peter didn't want any more band-aids, and did > > > the restructuring, but as you can see from the two other patches, it > > > makes it a bit more high risk. > > > > If those are known to work, why can't I take them as-is? > > If they apply without tweaks, I say "Go for it" ;-) > > My worry is that they may have other unknown dependencies. And I only > looked at what was applied between 4.19 and 5.4 mainline. I haven't > looked at what else may have been backported to fix the above three > commits. I tried to backport the above series, and quickly gave up, as yes, you are right, the dependencies are deep and messy from what I can tell. WHat's wrong with just moving to 5.4? :) thanks, greg k-h